As the threat of Sunnis extremists invading Shiite territory and getting closer to Baghdad grows, men from across the capital are pouring into military recruitment stations to join the fight. Anderson speaks to a few young recruits about why they decided to sign up to fight against ISIS.

Editor's Note: This report contains images that some people may find disturbing.

Iraq is dealing with a crisis that threatens to tear the country apart. As dictators across the Middle East fall, many of those nations are now descending into chaos. This is raising the uncomfortable question: are dictators needed to keep a tight lid on disorder? Randi Kaye takes a closer look.

ISIS now controls Iraq's second largest city, part of the country's largest oil refinery and a territory larger than the state of Israel. ISIS militants claim they killed 1,700 prisoners. U.S. security officials worry that they could target the U.S. next. Martin Chulov got an inside look at how ISIS is organized and how the group operates. He wrote about it in the Guardian and discussed it with Anderson.

Anderson Cooper is in Baghdad where ISIS militants are just outside the city. The terror group now controls part of one of Iraq's key oil refineries. As Iraq looks for a way out of this crisis, faith and trust in the government remains low. Anderson has the latest on the battle against ISIS.

U.S. has begun reconnaissance flights over ISIS targets. What does this say about the Obama administration's plan for dealing with the Iraq crisis? Anderson discussed this with Chief National Security Correspondent Jim Sciutto and retired Major General James 'Spider' Marks.

Former British Prime Minister Tony Blair is taking heat for recently claiming that the 2003 Iraq invasion was in no way responsible for the current crisis. In an interview with Anderson Cooper, Blair defended that remark and he tried to explain the complexity of the situation:

"What our intervention in Iraq shows is how difficult intervention is. What events in Syria show is how difficult non-intervention is."

Sunni Iraqis make up the majority of ISIS's forces, but analysts say a growing number of foreign fighters are joining their ranks. That even includes some Americans. ISIS is producing videos that urge westerners to join the fight, and thousands may be answering the call. Pamela Brown looks at the danger these fighters pose on the battlefield and in their home countries.

What could be done about all of this? Anderson spoke with National Security Analyst Fran Townsend, who's a member of the DHS and CIA external advisory committees and Maajid Nawaz, a former Islamist militant who is now an author and chairman of the Quiliam Foundation.

Nuri Al-Maliki spent decades in exile before the fall of Saddam Hussein. Since taking office in 2006, Prime Minister Maliki has enjoyed the praise and support of both President Bush and President Obama. Now he is in the middle of a crisis that could tear Iraq apart. Randi Kaye has his story.

Anderson looks into how Prime Minister Maliki's actions are motivating Sunni groups to back ISIS. He spoke with Ken Pollack, a Senior Fellow at the Saban Center for Middle East Policy, along with James Jeffrey, a former U.S. Ambassador to Iraq.

As hundreds of thousands of people across Iraq flee ISIS fighters, some are ready to take up arms against the militants. Anderson walked through Baghdad and spoke to one man who vowed to be a thorn in ISIS' eye.

ISIS is one of the world's most dangerous terror groups and it is possibly the richest. ISIS is cutting a deadly trail across Iraq and cashing in at the same time. Randi Kaye reports on how ISIS amassed hundreds of millions of dollars.

As ISIS threatens Baghdad, there are growing security concerns for the U.S. Embassy in the capital. It is a virtual city within a city with more than 5,000 workers and is America's largest diplomatic post. Tom Foreman takes a look at what it would take to keep the U.S. Embassy in Baghdad safe if ISIS attack.